Improvement of the quality of graphene-capped InAs/GaAs quantum dots

Journal Article · Sat Jun 07 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4880338· OSTI ID:22304223

Othmen, Riadh; Rezgui, Kamel; Ajlani, Hosni; Oueslati, Meherzi ^[1]; Cavanna, Antonella; Madouri, Ali ^[2]; Arezki, Hakim; Gunes, Fethullah ^[3]

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1. Faculté des Sciences de Tunis, Université de Tunis El Manar, Campus, 2092 El Manar Tunis (Tunisia)
2. CNRS/LPN, Route de Nozay, F-91460 Marcoussis (France)
3. Laboratoire de Génie Electrique de Paris, 11, rue Joliot Curie Plateau de Moulon, 91192 Gif sur Yvette (France)

In this paper, we study the transfer of graphene onto InAs/GaAs quantum dots (QDs). The graphene is first grown on Cu foils by chemical vapor deposition and then polymer Polymethyl Methacrylate (PMMA) is deposited on the top of graphene/Cu. High quality graphene sheet has been obtained by lowering the dissolving rate of PMMA using vapor processing. Uncapped as well as capped graphene InAs/GaAs QDs have been studied using optical microscopy, scanning electron microscopy, and Raman spectroscopy. We gather from this that the average shifts Δω of QDs Raman peaks are reduced compared to those previously observed in graphene and GaAs capped QDs. The encapsulation by graphene makes the indium atomic concentration intact in the QDs by the reduction of the strain effect of graphene on QDs and the migration of In atoms towards the surface. This gives us a new hetero-structure graphene–InAs/GaAs QDs wherein the graphene plays a key role as a cap layer.

• OSTI ID: 22304223
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 21 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMS
CHEMICAL VAPOR DEPOSITION
COPPER
ENCAPSULATION
FOILS
GALLIUM ARSENIDES
GRAPHENE
INDIUM ARSENIDES
LAYERS
MIGRATION
OPTICAL MICROSCOPY
PMMA
QUANTUM DOTS
RAMAN SPECTROSCOPY
REDUCTION
SCANNING ELECTRON MICROSCOPY
STRAINS
SUBSTRATES
SURFACES